package com.ukefu.util;

import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

public class DES3 {

	private static final String KEY_ALGORITHM = "DESede";
	private static final String DEFAULT_CIPHER_ALGORITHM = "DESede/ECB/PKCS5Padding";// 默认的加密算法

	/**
	 * DESede 加密操作
	 *
	 * @param content
	 *            待加密内容
	 * @param key
	 *            加密密钥
	 * @return 返回Base64转码后的加密数据
	 */
	public static String encrypt(String content, String key) {
		try {
			Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
			// 创建密码器
			byte[] byteContent = content.getBytes("utf-8");
			cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(key));
			// 初始化为加密模式的密码器
			byte[] result = cipher.doFinal(byteContent);// 加密
			return Base64.encodeBase64String(result);// 通过Base64转码返回
		} catch (Exception ex) {
			ex.printStackTrace();
		}
		return null;
	}

	/**
	 * } } DESede 解密操作
	 *
	 * @param content
	 * @param key
	 * @return
	 */
	public static String decrypt(String content, String key) {
		try {
			// 实例化
			Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM); // 使用密钥初始化，设置为解密模式
			cipher.init(Cipher.DECRYPT_MODE, getSecretKey(key)); // 执行操作
			byte[] result = cipher.doFinal(Base64.decodeBase64(content));
			return new String(result, "utf-8");
		} catch (Exception ex) {
			ex.printStackTrace();
		}
		return null;
	}

	/**
	 * } 生成加密秘钥
	 *
	 * @return
	 */
	private static SecretKeySpec getSecretKey(final String key) {
		// 返回生成指定算法密钥生成器的KeyGenerator 对象
		KeyGenerator kg = null;
		try {
			kg = KeyGenerator.getInstance(KEY_ALGORITHM);
			kg.init(new SecureRandom(key.getBytes()));
			// 生成一个密钥
			SecretKey secretKey = kg.generateKey();
			return new SecretKeySpec(secretKey.getEncoded(), KEY_ALGORITHM);
			// 转换为DESede专用密钥
		} catch (NoSuchAlgorithmException ex) {
			ex.printStackTrace();
		}
		return null;
	}

	public static void main(String[] args) {
		String content = "测试3DES";
		String key = "key";
		System.out.println("content:" + content);
		String s1 = DES3.encrypt(content, key);
		System.out.println("加密:" + s1);
		System.out.println("解密:" + DES3.decrypt(s1, key));
	}
}
